- Email: [email protected]
Contamination of roadside vegetation with lead cadmium and zinc
Chemosphere, Vol.14, No.3/4, pp 271-277, Printed in Great Britain
1985
0045-6535/85 $3.OO + .OO 01985 Pergamon Press Ltd.
CONTAMINATION OF ROADSIDE VEGETATIONWITH LEAD CADMIUMAND ZINC K. Fytianos, G. V a s i l i k i o t i s and V. Samanidou Environmental Pollution Control Laboratory, Aristotelian University of Thessaloniki, Thessaloniki, Greece.
There are several ways in which heavy metals may pollute our environment. Easily v o l a t i l i z e d at temperatures occurring in common industrial processes Pb, Cd and Zn are present in the
atmo-
sphere, especially near urban areas. The present report deals with Pb, Cd and Zn contamination of roadside grass and vegetation caused by motor vehicles. Cadmium is the most dangerous of the metals where human health is concerned, while hazards due to environmental Pb have also been reported (Kehoe, R.A et al. 1961; Schroeder 1966;Carroll 1966). Other possible sources of grass and vegetation contamination p a r t i cularly in connection with food quality are certain agricultural chemicals and regularly applied f e r t i l i z e r s containing these metals (Barrows 1966). Due to their presence in the a~mosphere the metals reach soil plant cover by precipitation (Terhaar 1967). Reports have been made about vegetation damage caused by t r a f f i c . Metals in the form of dust on leaves prevent certain basic processes from being carried out such as assimilation and transpiration (Suchodoller 1967). I t must be noticed here that in F.R.G. the use of grass in cattle -breedingis forbidden within 100 m of both sides of highways, because of the high concentration in
Pb (Moll 1978). Previous investiga-
tion (Kehoe 1961;Lagerwerff 1970) have shown that the concentration of Pb in plants and grass depends on several factors such as t r a f f i c density, distance from t r a f f i c , direction of wind and other meteorological factors and f i n a l l y season and time of sampling. MATERIALS AND METHODS Plant and grass samples were collected from a wide range of the roadsides at varying dinstances in the area around the c i t y of Thessaloniki during the summer of 1984. A total number of 35 d i f f e r e n t locations were selected for this purpose (Fig. 1). The samples were dried overnight at 90°C. 2 - 3 g of the dried sample were ground, placed in an 150 mL Erlenmeyer flask and soaked with 100 mL d i s t i l l e d water. Then 25 mL conc. HNO3 and 10 mL HCLO4 were added and the flasks were
271
"10
,11
to K I I k l s
Fig.l. Map of Thessaloniki region with the sampling stations.
Katerlnl
highway to Athens
highway to Yugoslavia
C
to Serrea K~vaia
i~J
~J
273
120
Zn
z~ zJ1 Zn
.bz,,
n
L .
.
.
.
A
.
.
.
0m
.
.
10m
.
.
.
30m
Highways Fig.2
"
.
om
30m
~m
0m
Industrial area
i
10m
3Ore
Roads in the City
Concentrations of Pb,Zn and Cd in grass samples as a of distance from road.
function
A : Area not affected from t r a f f i c . ....... From EEC suggested maximum Pb concentration in grass(d.w.) for cattle breeding Zn 180
grass samples I~ plant samples
~
mb
zn
too
I.
.
.
.
.
.
.
.
. ~
Om
Highways
.............
-9[
-~ .............. 0m
Industrial area
0m
Roads in the City
Fig.3. Concentrations of Pb,Zn and Cd in grass and plant samples in different areas of Thessaloniki.
274
stored at room temperature overnight. In this way partial digestion of the organic matter is accomplished without foaming. The solutions were next boiled on a sand bath until they became transparent and the total acid volume reduced to 5 mL. After cooling, the samples were filtered and the f i l t r a t e s were analysed for Pb, Cd and Zn by AAS. The same samples were treated and analysed after water rinsing to discover its effect on the metal content. RESULTS AND DISCUSSION The results, which are averages of duplicate samplings and analyses, are given in tables I and 2. The concentrations of Pb and Zn in grass samples and vegetation decreased according to distance from the road, indicating their relation to t r a f f i c (Fig 2). Regarding Cd, no significant concentration differences were observed. The metal concentration gradients with distance followed the order Pb>Zn>Cd. The Pb concetrations also decreased after rinsing the samples (up to 40 %) while for Zn the diminution was up to 60 %. These significant differences must be attributed to the removal, by a rinsing process, of the metal rich dust which resides on the grass and the leaves of plants. Once more, no noteworthy differences were detected for Cd (Fig 3). Considering the distance from the road, a decrease of up to 70 % has been confirmed for both Pb and Zn concentrations at 30 m from the roadside. The variation of analogous results, indicates differences in local t r a f f i c densities with respect to dinstance and treatment between different sampling locations. Main roads and crossroads and in particular highways, bear much higher metal concentrations than side roads (Fig 4).
BBnot rinsed samples [] rinsed samples
2(1
34
32
(Sampling
24
~'~
26
28
22
Stations )
Fig. 4. Concentrations of Pb in plant samples (Nerium oleander) in cross roads in the city of Thessaloniki. Even within busy highways there are differences in metal concentrations. The roads situated near the industrial area of Thessaloniki contain high Pb and Zn concentrations, most probably in view of the airpollutants originating from various factories in this region. These factories constitute oil refinery, steel, plant f e r t i l i z e r and other metal industries located in the west of the city. Furthermore, the gasoline used in Thessaloniki Contains 0,4 g Pb/L. On the contrary,
0
0
0
0
0
0
0
0
~°
0
~o
•-4 f'~
~
0
0
~
0
0
0
0
0
~
0
0
0
0
0
0
0
~
0
0
~
0
0
0
0
0
~
0
0
0
0
~
0
0
0
~n
O)
"v"
0
0
0
0
0
0
~°
c.e
e-
3
_g
g
_g
0
...,j
_g
fD e~
--h ~.
3
~° e.-,
"I 0
0
~ ¢.~
-h "I 0 3 0
0 ,-4¢g ::~ e*
¢'D
-.s
~
~
ff'~
OJ
..J.
N
I-~
~°
o -'h
.d. 0
.-h
OJ
.-4 O~ O" .-d
OlD
S
...~.
_g
¢'D
g
OJ
0 r~
O.
OJ
0
-h -S 0 3
0
-4 01
276
Table 2. Leed, Zinc and Cadmium contents (pg/g d.w.) in plant samples (Nerium oleander)
Sampling Stations
Maters Pb Zn Cd from road not washed washed not washed washed not washed washed
I. Industrial area 1
0
99,0
49,9
83,2
62,7
3,0
2,8
If. Highways 3 9 12
0 0 0
56,1 24,2 125,4
29,9 21,5 107,3
86,4 51,6 69,7
79,3 47,6 63,2
2,7 2,8 4,2
2,5 2,6 3,7
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 30 0 10 30
136,8 21,0 38,5 20,6 42,1 21,0 60,0 97,8 64,1 31,6 66,0 30,9 62,3 37,1 55,4 50,4 35,2 24,0 51,4 24,6 15,9
89,4 17,5 28,0 17,6 31,7 17,4 33,3 51,5 55,8 27,9 43,5 25,9 29,8 20,5 29,8 33,3 29,7 21,2 24,7 13,3 15,6
114,3 52,6 48,1 60,8 71,1 62,3 62,7 77,7 53,6 56,2 80,7 61,8 57,8 44,2 49,2 54,0 41,4 44,6 70,0 41,6 41,6
81,7 52,6 42,9 55,5 48,4 52,2 53,5 60,1 67,1 41,8 59,2 41,4 33,3 32,5 48,4 35,0 41,0 37,1 51,2 36,8 37,1
4,3 3,9 4,0 3,3 3,9 4,4 3,8 4,0 2,9 3,0 4,0 3,4 4,3 3,4 3,5 3,2 3,5 3,7 2,8 3,5 2,8
3,3 3,3 4,0 3,3 3,9 4,0 2,8 3,7 2,6 2,6 3,8 2,9 2,6 2,4 2,6 2,5 3,3 3,5 2,5 2,7 2,8
I I I . City of Thessaloniki 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35
277
quite reasonable low concentrations of a l l the studied metals were determined in samples from areas beyond the industrial area and the busy roads (Pb = 10.5, Zn = 31,4, Cd = 2,1 ppm). The contamination of grass near highways at bends or steep slopes may readily be explained in terms of the previous arguments. Parallel conclusions can be drawn from grass and plant sample determinations keeping the sampling factors the same in both cases, although the l a t t e r seems to be less polluted. From the data presented in this study, i t may be concluded that there exists, to a severe degree, pollution of grass and plants especially with Pb and Zn and to a lesser degree with Cd. The contamination is more pronounced near the industrial area, busy roads and cross roads.Moreover, highway samples present contamination at a much lower level than those inside the c i t y . Finally the concentrations of Pb and Zn in grass and plant samples decrease with distance from the road. REFERENCES Barrows, H.L. (1966). vation 21, 211 - 216.
Soil Pollution and i t s influence on plant Quality. J. Soil Water Conser-
Carroll, R.E. (1966). The relationship of Cadmium in the A i r to Cardio vascular disease Death Rates. J. Amer. Med. Assoc. 198, 267 - 269. Kehoe, R.A. (1961). The metabolism of lead in man in health and disease.
The Harben Lectures.
J.Royal I n s t i t . Public Health and Hyg. 24, 177 - 203. Lagerwerff, J.V. and Specht. A.W. (1970). cadmium, nickel, lead and Zink. Moll, W.L. (1978).
Contamination of roadside soil and vegetation with
Environ. Sci. Technology 4, 583 - 586.
Taschenbuchfur Umweltschutz, Steinkopff Verlag, W. Germany.
Schroeder, H.A. (1966). Assoc. 195, 81 - 85.
Municipal Drinking Water and Cardiovascular Death Rates. J.Amer. Med.
Suchodoller, A. (1967). Untersuchungen ~ber den Bleigehalt von Pflanzen in der N~he von Strassen und ~ber die Aufnahme und Translokation von Blei durch Pflanzen. Berichte der Schweiz. Botanischen Cesellschaff 77, 266 - 309. Terhaar G.L. (1967). Lead and Lead - 210 in rainwater. Nature 216, 353 - 355. (Received in The Netherlands
10 October 1984; accepted 24 January 1985)
1985
0045-6535/85 $3.OO + .OO 01985 Pergamon Press Ltd.
CONTAMINATION OF ROADSIDE VEGETATIONWITH LEAD CADMIUMAND ZINC K. Fytianos, G. V a s i l i k i o t i s and V. Samanidou Environmental Pollution Control Laboratory, Aristotelian University of Thessaloniki, Thessaloniki, Greece.
There are several ways in which heavy metals may pollute our environment. Easily v o l a t i l i z e d at temperatures occurring in common industrial processes Pb, Cd and Zn are present in the
atmo-
sphere, especially near urban areas. The present report deals with Pb, Cd and Zn contamination of roadside grass and vegetation caused by motor vehicles. Cadmium is the most dangerous of the metals where human health is concerned, while hazards due to environmental Pb have also been reported (Kehoe, R.A et al. 1961; Schroeder 1966;Carroll 1966). Other possible sources of grass and vegetation contamination p a r t i cularly in connection with food quality are certain agricultural chemicals and regularly applied f e r t i l i z e r s containing these metals (Barrows 1966). Due to their presence in the a~mosphere the metals reach soil plant cover by precipitation (Terhaar 1967). Reports have been made about vegetation damage caused by t r a f f i c . Metals in the form of dust on leaves prevent certain basic processes from being carried out such as assimilation and transpiration (Suchodoller 1967). I t must be noticed here that in F.R.G. the use of grass in cattle -breedingis forbidden within 100 m of both sides of highways, because of the high concentration in
Pb (Moll 1978). Previous investiga-
tion (Kehoe 1961;Lagerwerff 1970) have shown that the concentration of Pb in plants and grass depends on several factors such as t r a f f i c density, distance from t r a f f i c , direction of wind and other meteorological factors and f i n a l l y season and time of sampling. MATERIALS AND METHODS Plant and grass samples were collected from a wide range of the roadsides at varying dinstances in the area around the c i t y of Thessaloniki during the summer of 1984. A total number of 35 d i f f e r e n t locations were selected for this purpose (Fig. 1). The samples were dried overnight at 90°C. 2 - 3 g of the dried sample were ground, placed in an 150 mL Erlenmeyer flask and soaked with 100 mL d i s t i l l e d water. Then 25 mL conc. HNO3 and 10 mL HCLO4 were added and the flasks were
271
"10
,11
to K I I k l s
Fig.l. Map of Thessaloniki region with the sampling stations.
Katerlnl
highway to Athens
highway to Yugoslavia
C
to Serrea K~vaia
i~J
~J
273
120
Zn
z~ zJ1 Zn
.bz,,
n
L .
.
.
.
A
.
.
.
0m
.
.
10m
.
.
.
30m
Highways Fig.2
"
.
om
30m
~m
0m
Industrial area
i
10m
3Ore
Roads in the City
Concentrations of Pb,Zn and Cd in grass samples as a of distance from road.
function
A : Area not affected from t r a f f i c . ....... From EEC suggested maximum Pb concentration in grass(d.w.) for cattle breeding Zn 180
grass samples I~ plant samples
~
mb
zn
too
I.
.
.
.
.
.
.
.
. ~
Om
Highways
.............
-9[
-~ .............. 0m
Industrial area
0m
Roads in the City
Fig.3. Concentrations of Pb,Zn and Cd in grass and plant samples in different areas of Thessaloniki.
274
stored at room temperature overnight. In this way partial digestion of the organic matter is accomplished without foaming. The solutions were next boiled on a sand bath until they became transparent and the total acid volume reduced to 5 mL. After cooling, the samples were filtered and the f i l t r a t e s were analysed for Pb, Cd and Zn by AAS. The same samples were treated and analysed after water rinsing to discover its effect on the metal content. RESULTS AND DISCUSSION The results, which are averages of duplicate samplings and analyses, are given in tables I and 2. The concentrations of Pb and Zn in grass samples and vegetation decreased according to distance from the road, indicating their relation to t r a f f i c (Fig 2). Regarding Cd, no significant concentration differences were observed. The metal concentration gradients with distance followed the order Pb>Zn>Cd. The Pb concetrations also decreased after rinsing the samples (up to 40 %) while for Zn the diminution was up to 60 %. These significant differences must be attributed to the removal, by a rinsing process, of the metal rich dust which resides on the grass and the leaves of plants. Once more, no noteworthy differences were detected for Cd (Fig 3). Considering the distance from the road, a decrease of up to 70 % has been confirmed for both Pb and Zn concentrations at 30 m from the roadside. The variation of analogous results, indicates differences in local t r a f f i c densities with respect to dinstance and treatment between different sampling locations. Main roads and crossroads and in particular highways, bear much higher metal concentrations than side roads (Fig 4).
BBnot rinsed samples [] rinsed samples
2(1
34
32
(Sampling
24
~'~
26
28
22
Stations )
Fig. 4. Concentrations of Pb in plant samples (Nerium oleander) in cross roads in the city of Thessaloniki. Even within busy highways there are differences in metal concentrations. The roads situated near the industrial area of Thessaloniki contain high Pb and Zn concentrations, most probably in view of the airpollutants originating from various factories in this region. These factories constitute oil refinery, steel, plant f e r t i l i z e r and other metal industries located in the west of the city. Furthermore, the gasoline used in Thessaloniki Contains 0,4 g Pb/L. On the contrary,
0
0
0
0
0
0
0
0
~°
0
~o
•-4 f'~
~
0
0
~
0
0
0
0
0
~
0
0
0
0
0
0
0
~
0
0
~
0
0
0
0
0
~
0
0
0
0
~
0
0
0
~n
O)
"v"
0
0
0
0
0
0
~°
c.e
e-
3
_g
g
_g
0
...,j
_g
fD e~
--h ~.
3
~° e.-,
"I 0
0
~ ¢.~
-h "I 0 3 0
0 ,-4¢g ::~ e*
¢'D
-.s
~
~
ff'~
OJ
..J.
N
I-~
~°
o -'h
.d. 0
.-h
OJ
.-4 O~ O" .-d
OlD
S
...~.
_g
¢'D
g
OJ
0 r~
O.
OJ
0
-h -S 0 3
0
-4 01
276
Table 2. Leed, Zinc and Cadmium contents (pg/g d.w.) in plant samples (Nerium oleander)
Sampling Stations
Maters Pb Zn Cd from road not washed washed not washed washed not washed washed
I. Industrial area 1
0
99,0
49,9
83,2
62,7
3,0
2,8
If. Highways 3 9 12
0 0 0
56,1 24,2 125,4
29,9 21,5 107,3
86,4 51,6 69,7
79,3 47,6 63,2
2,7 2,8 4,2
2,5 2,6 3,7
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 30 0 10 30
136,8 21,0 38,5 20,6 42,1 21,0 60,0 97,8 64,1 31,6 66,0 30,9 62,3 37,1 55,4 50,4 35,2 24,0 51,4 24,6 15,9
89,4 17,5 28,0 17,6 31,7 17,4 33,3 51,5 55,8 27,9 43,5 25,9 29,8 20,5 29,8 33,3 29,7 21,2 24,7 13,3 15,6
114,3 52,6 48,1 60,8 71,1 62,3 62,7 77,7 53,6 56,2 80,7 61,8 57,8 44,2 49,2 54,0 41,4 44,6 70,0 41,6 41,6
81,7 52,6 42,9 55,5 48,4 52,2 53,5 60,1 67,1 41,8 59,2 41,4 33,3 32,5 48,4 35,0 41,0 37,1 51,2 36,8 37,1
4,3 3,9 4,0 3,3 3,9 4,4 3,8 4,0 2,9 3,0 4,0 3,4 4,3 3,4 3,5 3,2 3,5 3,7 2,8 3,5 2,8
3,3 3,3 4,0 3,3 3,9 4,0 2,8 3,7 2,6 2,6 3,8 2,9 2,6 2,4 2,6 2,5 3,3 3,5 2,5 2,7 2,8
I I I . City of Thessaloniki 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35
277
quite reasonable low concentrations of a l l the studied metals were determined in samples from areas beyond the industrial area and the busy roads (Pb = 10.5, Zn = 31,4, Cd = 2,1 ppm). The contamination of grass near highways at bends or steep slopes may readily be explained in terms of the previous arguments. Parallel conclusions can be drawn from grass and plant sample determinations keeping the sampling factors the same in both cases, although the l a t t e r seems to be less polluted. From the data presented in this study, i t may be concluded that there exists, to a severe degree, pollution of grass and plants especially with Pb and Zn and to a lesser degree with Cd. The contamination is more pronounced near the industrial area, busy roads and cross roads.Moreover, highway samples present contamination at a much lower level than those inside the c i t y . Finally the concentrations of Pb and Zn in grass and plant samples decrease with distance from the road. REFERENCES Barrows, H.L. (1966). vation 21, 211 - 216.
Soil Pollution and i t s influence on plant Quality. J. Soil Water Conser-
Carroll, R.E. (1966). The relationship of Cadmium in the A i r to Cardio vascular disease Death Rates. J. Amer. Med. Assoc. 198, 267 - 269. Kehoe, R.A. (1961). The metabolism of lead in man in health and disease.
The Harben Lectures.
J.Royal I n s t i t . Public Health and Hyg. 24, 177 - 203. Lagerwerff, J.V. and Specht. A.W. (1970). cadmium, nickel, lead and Zink. Moll, W.L. (1978).
Contamination of roadside soil and vegetation with
Environ. Sci. Technology 4, 583 - 586.
Taschenbuchfur Umweltschutz, Steinkopff Verlag, W. Germany.
Schroeder, H.A. (1966). Assoc. 195, 81 - 85.
Municipal Drinking Water and Cardiovascular Death Rates. J.Amer. Med.
Suchodoller, A. (1967). Untersuchungen ~ber den Bleigehalt von Pflanzen in der N~he von Strassen und ~ber die Aufnahme und Translokation von Blei durch Pflanzen. Berichte der Schweiz. Botanischen Cesellschaff 77, 266 - 309. Terhaar G.L. (1967). Lead and Lead - 210 in rainwater. Nature 216, 353 - 355. (Received in The Netherlands
10 October 1984; accepted 24 January 1985)